Medical device disinfecting system and method

ABSTRACT

A system for disinfecting a medical device is provided. The system includes a light source that generates light having at least one wavelength between about 100 nm and about 500 nm. The system further includes at least one cylindrical optical diffuser disposed in optical communication with at least one interior channel of a medical device, the at least one cylindrical optical diffuser having an outer surface and an end optically coupled to the light source. The at least one cylindrical optical diffuser is configured to scatter guided light through the outer surface to form a light diffuser portion having a length that emits substantially uniform radiation over its length.

This application is a continuation application and claims the benefit ofpriority under 35 U.S.C. § 120 of U.S. patent application Ser. No.15/753,824 filed on Feb. 20, 2018, which is a US 371 ofPCT/US2016/047490 filed on Aug. 18, 2016, which claims the benefit ofpriority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No.62/278,197 filed on Jan. 13, 2016 and U.S. Provisional Application Ser.No. 62/208,239 filed on Aug. 21, 2015, the contents of which are reliedupon and incorporated herein by reference in their entirety.

FIELD

The present disclosure generally relates to medical devices, medicaldevice disinfecting systems, and disinfection methods. Moreparticularly, the present disclosure relates to medical devices havingat least one cylindrical optical diffuser, medical device disinfectingsystems including at least one cylindrical optical diffuser, anddisinfection methods using at least one cylindrical optical diffuser.

BACKGROUND

Bacteria that exist in health care settings differ significantly frombacteria found in a general community setting, primarily in theirresistance to antibiotic therapy. In many ways, the hospital environmentcontributes to the problem by harboring virulent strains of bacteria,fungi, and viruses. This is at least partly a result of the fact thatmany conventional disinfection methods are ineffective and may actuallyspread contaminants. Additionally, when subjected to the methods ofdisinfection on a regular basis, bacteria develop resistance to themethods over time. These contaminants are present on objects, and inparticular, medical devices in the hospital setting. For medical devicesthat cannot be disposed of after a single use, the devices must bedisinfected between uses. Additionally, some medical devices which areplaced partially inside the body and partially outside the body for anextended period of time are at an increased risk of infection.

Examples of such medical devices are flexible and rigid endoscopes. Somesystems for cleaning such endoscopes are configured to allow theendoscope to be housed in a processing tank to be cleaned anddisinfected with the use of liquid detergent and disinfectant solution.However, endoscopes may have a plurality of interior channels or lumensthat are difficult to reach and disinfect. Such channels are used toinject liquid irrigants, suction, and to pass flexible surgicalinstruments such as biopsy forceps.

Some mechanical aids have been developed for use in cleaning theinterior channels or lumens of an endoscope. For example, brush devicesthat fit into interior channels or lumens are equipped with bristlesthat project from a central shaft to provide mechanical abrasion to thesurfaces of the interior channels or lumens of an endoscope. Also,sponge devices that fit into interior channels or lumens spreadcontamination into a substantially uniform film on the surfaces of theinterior channels or lumens of an endoscope so that enzymatic cleanerscan more efficiently and uniformly digest the contaminating material.However, the bristles of the brush devices do not provide uniformcontact with the surfaces of the interior channels or lumens of anendoscope, and the sponge devices merely spread contaminants and are notconfigured to provide the mechanical force needed to remove contaminantsadhering to surfaces of the interior channels or lumens of an endoscope.

SUMMARY

According to an embodiment of the present disclosure, a system fordisinfecting a medical device is provided. The system includes a lightsource that generates light having at least one wavelength between about100 nm and about 500 nm. The system further includes at least onecylindrical optical diffuser disposed in optical communication with atleast one interior channel of a medical device, the at least onecylindrical optical diffuser having an outer surface and an endoptically coupled to the light source. The at least one cylindricaloptical diffuser is configured to scatter guided light through the outersurface to form a light diffuser portion having a length that emitssubstantially uniform radiation over its length.

According to another embodiment of the present disclosure, a medicaldevice is provided. The medical device includes at least one interiorchannel and at least one cylindrical optical diffuser disposed inoptical communication with the least one interior channel, the at leastone cylindrical optical diffuser having an outer surface and an endoptically coupled to a light source. The at least one cylindricaloptical diffuser is configured to scatter guided light through the outersurface to form a light diffuser portion having a length that emitssubstantially uniform radiation over its length.

According to another embodiment of the present disclosure, adisinfection method is provided. The method includes inserting at leasta portion of at least one cylindrical optical diffuser into an interiorchannel of a medical device and introducing light from a light sourceinto an end of the at least one cylindrical optical diffuser opticallycoupled to the light source and emitting the light through the outersurface of the diffuser to illuminate a portion of the diffuser and toexpose the interior channel to the emitted light. The at least onecylindrical optical diffuser is configured to scatter guided lightthrough the outer surface to form a light diffuser portion having alength that emits substantially uniform radiation over its length, andto disinfect at least one surface of the interior channel.

Additional features and advantages will be set forth in the detaileddescription which follows, and in part will be readily apparent to thoseskilled in the art from that description or recognized by practicing theembodiments as described herein, including the detailed descriptionwhich follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary, and areintended to provide an overview or framework to understanding the natureand character of the claims. The accompanying drawings are included toprovide a further understanding, and are incorporated in and constitutea part of this specification. The drawings illustrate one or moreembodiment(s), and together with the description serve to explainprinciples and operation of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be understood more clearly from the followingdescription and from the accompanying figures, given purely by way ofnon-limiting example, in which:

FIG. 1 is a schematic side view of a section of an example embodiment oflight-diffusing optical fiber;

FIG. 2 is a schematic cross-section of the optical fiber of FIG. 1 asviewed along the direction 2-2;

FIG. 3A is a schematic illustration of relative refractive index plotversus fiber radius for an exemplary embodiment of light diffusingfiber;

FIG. 3B is a schematic illustration of relative refractive index plotversus fiber radius for another exemplary embodiment of light diffusingfiber;

FIG. 3C illustrates another exemplary embodiment of a light diffusingfiber;

FIGS. 4A and 4B depict fiber attenuation (loss) in dB/m versuswavelength (nm);

FIG. 5 is a schematic illustration of an endoscopic surgical systemaccording to an embodiment of the present disclosure;

FIG. 6 is a front view of a distal end face of an endoscope according toan embodiment of the present disclosure;

FIG. 7 is a schematic sectional view of a distal end of an endoscopeaccording to an embodiment of the present disclosure; and

FIG. 8 is a front view of a distal end face of an endoscope according toan embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiment(s), anexample(s) of which is/are illustrated in the accompanying drawings.Whenever possible, the same reference numerals will be used throughoutthe drawings to refer to the same or like parts.

The singular forms “a,” “an” and “the” include plural referents unlessthe context clearly dictates otherwise. The endpoints of all rangesreciting the same characteristic are independently combinable andinclusive of the recited endpoint. All references are incorporatedherein by reference.

Embodiments of the present disclosure relate to medical devices, medicaldevice disinfecting systems, and disinfection methods. Embodiments ofthe present disclosure include at least one cylindrical optical diffuserthat may transmit ultraviolet irradiation, or short wavelength visiblelight. As used herein, a cylindrical optical diffuser refers to adiffuser that emits light through its outer surface when light isintroduced into the diffuser as guided light. While some of theembodiments included herein describe “at least one cylindrical opticaldiffuser”, it should be understood that embodiments including aplurality of cylindrical optical diffusers are also comprehended. Asused herein, the term “ultraviolet” (UV) light is used for a wavelengthof light being less than about 400 nm, and the term “short wavelengthvisible light” is used for a wavelength of light being between about 400nm and about 500 nm. Ultraviolet light, particularly in the C bandwidth,when given in adequate doses is lethal to all known pathogens. As usedherein, the term “ultraviolet light in the C bandwidth” (UV-C) is usedfor a wavelength of light being utilized for its germicidal properties,the wavelength being between about 100 nm and about 290 nm.Additionally, recent studies have shown that short wavelength visiblelight, such as violet and blue light, is also lethal to bacteria, fungi,and viruses at certain doses. Such short wavelength visible light maybe, for example, between about 400 nm and about 450 nm, or between about405 nm and about 415 nm.

The cylindrical optical diffuser may be, for example, a side-emittingfiber, or a bundle of two or more side-emitting fibers. Side-emittingfibers can be, for example, a single plastic or glass core without anycladding or coating in which light sent into the core is lost throughthe side surfaces of the fiber because the light is not trapped orinternally guided. Side-emitting fiber may include scattering defectsintroduced into the fiber at various locations, such as by doping thecore of the fiber with small refractive and/or reflectivelight-scattering particles, or by modifying a surface of the core tohave surface features that scatter light out of the core. Examples oflight-emitting surface defects include serrations, notches, scratches,texture, roughness, corrugations, etching, abrasion, etc. Alternatively,the cylindrical optical diffuser may be a light diffusing optical fiber.As used herein, the term “light diffusing optical fiber” refers to aflexible optical waveguide configured to diffuse light out of the sidesof the fiber, such that light is guided away from the core of thewaveguide and through the outer surfaces of the waveguide to provideillumination.

Concepts relevant to the underlying principles of the claimed subjectmatter are disclosed in U.S. Patent Application Publication No. US2011/0122646 A1, which is incorporated in its entirety herein byreference. As described in greater detail below, exemplary lightdiffusing optical fiber may include a core, a primary cladding, and aplurality of nano-sized structures situated within the core or at acore-cladding boundary. The optical fiber further includes an outersurface, and an end configured to optically couple to a light source.The light diffusing optical fiber may be configured to scatter guidedlight via the nano-sized structures away from the core and through theouter surface, to form a light-source fiber portion having a length thatemits substantially uniform radiation over its length

The term “light source” refers to a laser, light emitting diode or othercomponent capable of emitting electromagnetic radiation that is eitherin the UV light range of wavelengths or is of a wavelength that caninteract with a luminophore to emit light in the UV light range ofwavelengths.

The term “luminophore” refers to an atom or chemical compound thatmanifests luminescence, and includes a variety of fluorophores andphosphors.

The following terms and phrases are used in connection with lightdiffusing fibers having nano-sized structures.

The “refractive index profile” is the relationship between therefractive index or the relative refractive index and the waveguide(fiber) radius.

The “relative refractive index percent” is defined asΔ(r)%=100×[n(r)² −n _(REF) ²)]/2n(r)²,where n(r) is the refractive index at radius r, unless otherwisespecified. The relative refractive index percent is defined at 850 nmunless otherwise specified. In one aspect, the reference index n_(REF)is silica glass with a refractive index of 1.452498 at 850 nm, inanother aspect it is the maximum refractive index of the cladding glassat 850 nm. As used herein, the relative refractive index is representedby Δ and its values are given in units of “%”, unless otherwisespecified. In cases where the refractive index of a region is less thanthe reference index n_(REF), the relative index percent is negative andis referred to as having a depressed region or depressed-index, and theminimum relative refractive index is calculated at the point at whichthe relative index is most negative unless otherwise specified. In caseswhere the refractive index of a region is greater than the referenceindex n_(REF), the relative index percent is positive and the region canbe said to be raised or to have a positive index.

An “updopant” is herein considered to be a dopant which has a propensityto raise the refractive index relative to pure undoped SiO₂. A“downdopant” is herein considered to be a dopant which has a propensityto lower the refractive index relative to pure undoped SiO₂. An updopantmay be present in a region of an optical fiber having a negativerelative refractive index when accompanied by one or more other dopantswhich are not updopants. Likewise, one or more other dopants which arenot updopants may be present in a region of an optical fiber having apositive relative refractive index. A downdopant may be present in aregion of an optical fiber having a positive relative refractive indexwhen accompanied by one or more other dopants which are not downdopants.

Likewise, one or more other dopants which are not downdopants may bepresent in a region of an optical fiber having a negative relativerefractive index.

The term “a-profile” or “alpha profile” refers to a relative refractiveindex profile, expressed in terms of Δ(r) which is in units of “%”,where r is radius, which follows the equation,Δ(r)=Δ(r _(o))(1−[r−r ₀|/(r ₁ −r _(o))]^(a)),where r_(o) is the point at which Δ(r) is maximum, r₁ is the point atwhich Δ(r) % is zero, and r is in the range r₁≤r≤r_(f), where Δ isdefined above, r₁ is the initial point of the a-profile, r_(f) is the isfinal point of the a-profile, and α is an exponent which is a realnumber.

As used herein, the term “parabolic” therefore includes substantiallyparabolically shaped refractive index profiles which may vary slightlyfrom an α value of 2.0 at one or more points in the core, as well asprofiles with minor variations and/or a centerline dip. In someexemplary embodiments, a is greater than 1.5 and less than 2.5, morepreferably greater than 1.7 and less than 2.3 and even more preferablybetween 1.8 and 2.3 as measured at 850 nm. In other embodiments, one ormore segments of the refractive index profile have a substantially stepindex shape with an α value greater than 8, more preferably greater than10 even more preferably greater than 20 as measured at 850 nm.

The term “nano-structured fiber region” describes a fiber having aregion or area with a large number of gas filled voids, or othernano-sized structures. The region or area may have, for example, morethan 50 voids, or more than 100 voids, or even more than 200 voids inthe cross-section of the fiber. The gas filled voids may contain, forexample, SO₂, Kr, Ar, CO₂, N₂, O₂, or mixture thereof. Thecross-sectional size (e.g., diameter) of nano-sized structures (e.g.,voids) as described herein may vary from about 10 nm to about 1.0 μm(for example, from about 50 nm to about 500 nm), and the length may varyfrom about 1.0 millimeter to about 50 meters (for example, from about2.0 mm to about 5.0 meters, or from about 5.0 mm to about 1.0 meters).

In standard single mode or multimode optical fibers, the losses atwavelengths less than 1300 nm are dominated by Rayleigh scattering.These Rayleigh scattering losses L_(s) are determined by the propertiesof the material and are typically about 20 dB/km for visible wavelengths(400-700 nm). Rayleigh scattering losses also have a strong wavelengthdependence (i.e., L_(S) oc 1/

⁴, see FIG. 4B, comparative fiber A), which means that at least about1.0 km to about 2.0 km of the fiber is needed to dissipate more than 95%of the input light. Shorter lengths of such fiber would result in lowerillumination efficiency, while using long lengths (about 1.0 km to about2.0 km, or more) can be more costly and can be difficult to manage.

In certain configurations of lighting applications it is desirable touse shorter lengths of fiber, for example, having a length of about 0.02meters to about 100 meters. This requires an increase of scattering lossfrom the fiber, while being able to maintain good angular scatteringproperties (uniform dissipation of light away from the axis of thefiber) and good bending performance to avoid bright spots at fiberbends. A desirable attribute of at least some of the embodimentsdescribed herein is uniform and high illumination along the length ofthe fiber illuminator. Because the optical fiber is flexible, it allowsa wide variety of the illumination shapes to be deployed. It ispreferable to have no bright spots (due to elevated bend losses) at thebending points of the fiber, such that the illumination provided by thefiber does not vary by more than about 30%, preferably by less thanabout 20% and more preferably by less than about 10%. For example, in atleast some embodiments, the average scattering loss of the fiber isgreater than about 50 dB/km, and the scattering loss does not vary morethan about 30% (i.e., the scattering loss is within ±30% of the averagescattering loss) over any given fiber segment having a length of about0.2 meters. The average scattering loss of the fiber may be greater thanabout 50 dB/km with the scattering loss varying by less than about 30%over fiber segments of having a length of less than about 0.05 meters.The average scattering loss of the fiber may be greater than about 50dB/km with the scattering loss varying by less than about 30% over fibersegments having a length of about 0.01 meters. The average scatteringloss of the fiber may also be greater than about 50 dB/km with thescattering loss varying by less than about 20%, and preferably by lessthan about 10% over fiber segments having a length of about 0.01 meters.

According to embodiments of the present disclosure, the intensityvariation of the integrated light intensity diffused through sides ofthe fiber at the illumination wavelength is less than about 30% for thetarget length of the fiber, which can be, for example, between about0.02 meters to about 100 meters. The integrated light intensity diffusedthrough sides of the fiber at a specified illumination wavelength can bevaried by incorporating fluorescent material in the cladding or coating.The wavelength of the light scattering by the fluorescent material isdifferent from the wavelength of the light propagating in the fiber.

Fiber designs described herein include a nano-structured fiber region(region with nano-sized structures) placed in the core area of thefiber, or very close to the core. The fiber have scattering losses inexcess of about 50 dB/km, for example, greater than about 100 dB/km,greater than about 200 dB/km, greater than about 500 dB/km, greater thanabout 1000 dB/km, greater than about 3000 dB/km, or even greater thanabout 5000 dB/km. The scattering loss, and thus illumination, or lightradiated by the fiber, is uniform in angular space.

In order to reduce or to eliminate bright spots as bends in the fiber,it is desirable that the increase in attenuation at a 90° bend in thefiber is less than about 5.0 dB/turn, for example, less than about 3.0dB/turn, less than about 2.0 dB/turn, or even less than about 1.0dB/turn when the bend diameter is less than about 50 mm. In exemplaryembodiments, these low bend losses are achieved at even smaller benddiameters, for example, less than about 20 mm, less than about 10 mm, oreven less than about 5.0 mm. The total increase in attenuation may beless than about 1.0 dB per 90 degree turn at a bend radius of about 5.0mm.

The bending loss is equal to or is less than the intrinsic scatteringloss from the core of the straight fiber. The intrinsic scattering ispredominantly due to scattering from the nano-sized structures. Thus,according to at least the bend insensitive embodiments of optical fiber,the bend loss does not exceed the intrinsic scattering of the fiber.However, because scattering level is a function of bending diameter, thebending deployment of the fiber depends on its scattering level. Forexample, the fiber may have a bend loss of less than about 3.0 dB/turn,or even less than about 2.0 dB/turn, and the fiber can be bent in an arcwith a radius as small as about 5.0 mm without forming bright spots.

According to some embodiments, the light diffusing fiber 12 includes acore at least partially filled with nanostructures for scattering light,a cladding surrounding the core, and may optionally include at least onecoating surrounding the cladding. For example, the core and cladding maybe surrounded by primary and secondary coating layers, and/or by an inklayer. In some embodiments, the ink layer contains pigments to provideadditional absorption and modify the spectrum of the light scattered bythe fiber (e.g., to provide additional color(s) to the diffused light).In other embodiments, one or more of the coating layers comprisesmolecules which convert the wavelength of the light propagating throughthe fiber core such that the light emanating from the fiber coating(light diffused by the fiber) is at a different wavelength. In someembodiments, the ink layer and/or the coating layer may comprisephosphor in order to convert the scattered light from the core intolight of differing wavelength(s). In some embodiments, the phosphorand/or pigments are dispersed in the primary coating. In someembodiments the pigments are dispersed in the secondary coating, in someembodiments the pigments are dispersed in the primary and secondarycoatings. In some embodiments, the phosphor and/or pigments aredispersed in the polymeric cladding. Preferably, the nanostructures areSO₂ filled voids.

According to some embodiments, the optical fiber 12 includes a primarycoating, an optional secondary coating surrounding the primary coatingand/or an ink layer (for example located directly on the cladding, or onone of the coatings. The primary and/or the secondary coating mayinclude at least one of: pigment, phosphors, fluorescent material,hydrophilic material, light modifying material, or a combinationthereof.

According to some embodiments, a light diffusing optical fiber includes:(1) a glass core, a cladding, and a plurality of nano-sized structuressituated within said core or at a core-cladding boundary, the opticalfiber further including an outer surface and is configured to (i)scatter guided light via said nano-sized structures away from the coreand through the outer surface, (ii) have a scattering-inducedattenuation greater than 50 dB/km at illumination wavelength; and (2)one or more coatings, such that either the cladding or at least onecoating includes phosphor or pigments. According to some embodiments,these pigments may be capable of altering the wavelength of the lightsuch that the illumination (diffused light) provided by the outersurface of the fiber is of a different wavelength from that of the lightpropagating through fiber core. Preferably, the nanostructures are SO₂filled with voids.

According to some embodiments, a light diffusing optical fiber includes:a glass core, a cladding, and a plurality of nano-sized structuressituated within said core or at a core-cladding boundary. The opticalfiber further includes an outer surface and is configured to (i) scatterguided light via said nano-sized structures away from the core andthrough the outer surface, (ii) have a scattering-induced attenuationgreater than 50 dB/km at illumination wavelength; wherein the entirecore includes nano-sized structures. Such fiber may optionally includeat least one coating, such that either the cladding or at least onecoating includes phosphor or pigments. According to some embodiments thenanostructures are SO₂ filled voids.

According to some embodiments, a light diffusing optical fiber includes:a glass core, and a plurality of nano-sized structures situated withinsaid core such that the entire core includes nano-structures, theoptical fiber further including an outer surface and is configured to(i) scatter guided light via said nano-sized structures away from thecore and through the outer surface, (ii) have a scattering-inducedattenuation greater than 50 dB/km at illumination wavelength, whereinthe fiber does not include cladding. According to some embodiments, thenanostructures are SO₂ filled voids. The SO₂ filled voids in thenano-structured area greatly contribute to scattering (improvescattering).

According to some embodiments, a light diffusing optical fiber includes:a glass core, and a plurality of nano-sized structures situated withinsaid core such that the entire core includes nano-structures, saidoptical fiber further including an outer surface and is configured to(i) scatter guided light via said nano-sized structures away from thecore and through the outer surface, (ii) have a scattering-inducedattenuation greater than 50 dB/km at illumination wavelength whereinsaid fiber does not include cladding. According to some embodiments, thefiber optionally includes at least one coating such that either thecladding or the coating includes phosphor or pigments. According to someembodiments, the nanostructures are SO₂ filled voids. As stated above,the SO₂ filled voids in the nano-structured area greatly contribute toscattering (improve scattering).

FIG. 1 is a schematic side view of a section of a light diffusing fiberwith a plurality of voids in the core of the light diffusing opticalfiber 12 having a central axis, or centerline 16. FIG. 2 is a schematiccross-section of light diffusing optical fiber 12 as viewed along thedirection 2-2 in FIG. 1. Light diffusing optical fiber 12 can be, forexample, any one of the various types of optical fiber with anano-structured fiber region having periodic or non-periodic nano-sizedstructures 32. As an example, fiber 12 includes a core 20 divided intothree sections or regions. The sections or regions include a solidcentral region 22, a nano-structured ring portion 26, and an outer,solid portion 28 surrounding the nano-structured ring portion 26. Acladding 40 surrounds the core 20 and has an outer surface. The cladding40 can be, for example, a low index polymer such as UV or thermallycurable fluoroacrylate or silicone. The cladding 40 may include pure lowindex polymer. Additionally, the cladding 40 may also include pure orF-doped silica. The cladding 40 may have low refractive index to providea high numerical aperture (NA). The NA of fiber 12 may be equal to, orgreater than, the NA of a light source directing light into the fiber12. According to embodiments of the present disclosure, the NA of fiber12 may be greater than about 0.2, greater than about 0.3, or evengreater than about 0.4.

According to exemplary embodiments, the nano-structured ring portion 26of light diffusing fiber 12 comprises a glass matrix 31 with a pluralityof non-periodically disposed nano-sized structures 32 situated therein,such as the example voids shown in detail in the magnified inset of FIG.2. The voids may be periodically disposed, such as in a photonic crystaloptical fiber, wherein the voids typically have diameters between about1.0×10⁻⁶ m and about 1.0×10⁻⁵ m. The diameters of the voids may be atleast about 10 nm. The voids may also be non-periodically or randomlydisposed. The glass matrix 31 in nano-structured ring portion 26 may befor example, but without limitation, a fluorine-doped silica or anundoped pure silica.

The nano-sized structures 32 scatter the light away from the core 20 andtoward the outer surface of the fiber. The scattered light is thendiffused through the outer surface of the fiber 12 to provideillumination. That is, most of the light is diffused via scatteringthrough the sides of the fiber 12 along the fiber length. According toembodiments of the present disclosure, the fiber emits substantiallyuniform radiation over its length, and the fiber has ascattering-induced attenuation of greater than about 50 dB/km in theillumination wavelength. The scattering-induced attenuation may begreater than about 100 dB/km, greater than about 500 dB/km, greater thanabout 1000 dB/km, greater than about 2000 dB/km, or even greater thanabout 5000 dB/km in the illumination wavelength. Such scattering lossesare about 2.5 to about 250 times greater than the Rayleigh scatteringlosses in standard single mode and multimode optical fibers. The amountof the loss via scattering can be increased by changing the propertiesof the fiber 12, the width of the nano-structured region 26, and thesize and the density of the nano-sized structures 32.

In some embodiments, nano-structured region 26 includes pure silicaincluding a plurality of nano-sized structures 32. The minimum relativerefractive index and the average effective relative refractive index ofnano-structured region 26, taking into account the presence of anyvoids, may both be less than about −0.1%. The nano-sized structures 32,or voids, may contain one or more gases, such as argon, nitrogen,oxygen, krypton, or SO₂ or can contain a vacuum with substantially nogas. However, regardless of the presence or absence of any gas, theaverage refractive index in nano-structured region 26 is lowered due tothe presence of nano-sized structures 32. Nano-sized structures 32 canbe randomly or non-periodically disposed in the nano-structured region26. Alternatively, nano-sized structures 32 may be disposed periodicallyin the nano-structured region 26.

According to exemplary embodiments, solid central region 22 may includegermania doped silica, core inner annular region 28 may include puresilica, and the cladding 40 may include a glass or a low index polymer.The nano-structured region 26 may include a plurality of nano-sizedstructures 32 in pure silica, or, alternatively, nano-structured region26 may include a plurality of nano-sized structures 32 in fluorine-dopedsilica. According to other exemplary embodiments, the entire core 20 maybe nano-structured (filled with voids, for example), with the core 20being surrounded by the cladding 40. The core 20 may have a “step”refractive index delta, or may have a graded core profile, witha-profile having, for example, α-value between about 1.8 and about 2.3.

Glass in solid central region 22 and core inner annular region 28 mayinclude updopants, such as Ge, Al, Ti, P and combinations thereof. By“non-periodically disposed” or “non-periodic distribution,” it is meantthat when one takes a cross-section of the optical fiber, such as shownin FIG. 2, the nano-sized structures 32 are randomly or non-periodicallydistributed across a portion of the fiber. As an example, where thenano-sized structures 32 include voids, similar cross-sections taken atdifferent points along the length of the fiber will reveal differentcross-sectional void patterns, i.e., various cross-sections will havedifferent voids patterns, wherein the distributions of voids and sizesof voids do not match. That is, the voids are non-periodic, i.e., theyare not periodically disposed within the fiber structure. These voidsare stretched (elongated) along the length (i.e. parallel to thelongitudinal axis) of the optical fiber, but do not extend the entirelength of the entire fiber for typical lengths of transmission fiber.The voids may extend less than about 10 meters, and in many cases lessthan about 1.0 meter along the length of the fiber 12.

As described above, solid central region 22 and core inner annularregion 28 may include silica doped with germanium, i.e., germania-dopedsilica. Dopants other than germanium, singly or in combination, may beemployed within the core, and particularly at or near the centerline 16,of the optical fiber 12 to obtain the desired refractive index anddensity. The relative refractive index profile of the optical fiber 12disclosed herein is non-negative in core sections solid central region22 and core inner annular region 28. The optical fiber may contain noindex-decreasing dopants in the core. Additionally, the relativerefractive index profile of the optical fiber 12 may be non-negative insolid central region 22, nano-structured ring portion 26 and/or coreinner annular region 28.

The fiber 12 optionally includes a coating 44 surrounding the cladding40. Coating 44 may include a low modulus primary coating layer and ahigh modulus secondary coating layer. The coating 44 may be a polymercoating such as an acrylate-based or silicone based polymer. The coatingmay have a constant diameter along the length of the fiber. The coating44 may be designed to enhance the distribution and/or the nature oflight that passes from core 20 through cladding 40. The outer surface ofthe cladding 40 or the outer surface or the optional coating 44represents the sides 48 of fiber 12 through which light traveling in thefiber exits via scattering, as described herein. The coating 44 may be aresin that transmits UV light. For example, the resin that transmits UVlight may be, but is not limited to, resins having structutes of:tripropylene glycol diacrylate (TPGDA), polyester tetraacrylate,polyester hexaacrylate, aliphatic urethane diacrylate+hexanedioldiacrylate, polyether tetraacrylate, silicone diacrylate, siliconehexaacrylate, epoxydiacrylate based on bisphenol A, and epoxydiacrylatebased on bisphenol A+25% TPGDA.

According to embodiments of the present disclosure, core 20 may be agraded-index core, and may have a refractive index profile having aparabolic (or substantially parabolic) shape. For example, therefractive index profile of core 20 may have an α-shape with an α valueof about 2.0 as measured at 850 nm. The a value may be between about 1.8and about 2.3. According to other exemplary embodiments, one or moresegments of the refractive index profile may have a substantially stepindex shape with an α value greater than about 8.0, or greater thanabout 10, or even greater than about 20, as measured at 850 nm. Therefractive index of the core may have a centerline dip, wherein themaximum refractive index of the core 20, and the maximum refractiveindex of the entire optical fiber 12, is located a small distance awayfrom centerline 16. Alternatively, the refractive index of the core 20has no centerline dip, and the maximum refractive index of the core 20,and the maximum refractive index of the entire optical fiber 12, islocated at the centerline. According to exemplary embodiments, therefractive index of fiber 12 may have radial symmetry.

According to embodiments of the present disclosure, fiber 12 has asilica-based core 20 and depressed index (relative to silica) polymercladding 40. The low index polymer cladding 40 may have a relativerefractive index that is negative. For example, the relative refractiveindex of the low index polymer cladding 40 may be less than about −0.5%,or even less than about −1.0%. The cladding 40 may have a thickness ofgreater than about 20 μm, and the outer diameter of the cladding 40 mayhave a constant diameter along the length of fiber 12. The cladding 40may have a lower refractive index than the core 20, and a thickness ofgreater than about 10 μm. The cladding 40 may have an outer diameter of2×R_(max). For example, the cladding 40 may have an outer diameter ofabout 125 μm, such as between about 120 μm and 130 μm, or between about123 μm and about 128 μm. Alternatively, the cladding 40 may have adiameter that is less than about 120 μm, such as between about 60 μm andabout 80 μm.

The outer diameter R_(c) of core 20 may be constant along the length ofthe fiber 12. Additionally, the outer diameters of solid central region22, nano-structured ring portion 26 and core inner annular region 28 mayalso be constant along the length of the fiber 12. By constant, it ismeant that the variations in the diameter with respect to the mean valueare, for example, less than about 10%, or less than about 5.0%, or evenless than about 2.0%.

The outer radius R_(c) of core 20 may be greater than about 10 μm andless than about 600 μm, for example, between about 30 μm and about 400μm, or between about 125 μm and about 300 μm. The outer radius R_(c) ofcore 20 may be between about 50 μm and about 250 μm. As shown in FIG.3A, the outer radius R_(c) of core 20 is equal to the outer radius R₃ ofcore inner annular region 28.

The solid central region 22 may have a radius R₁ such that0.1R_(c)≤R₁≤0.9R_(c), or such that 0.5R_(c)≤R₁≤0.9R_(c). R₁ may bebetween about 24 μm and about 50 μm such that the diameter of the solidcentral region 22 is between about 48 μm and 100 μm. For example, R₁ maybe greater than about 24 μm, greater than about 30 μm, or even greaterthan about 40 μm. The nano-structured ring region 26 may have a width W₂such that 0.05R_(c)≤W₂≤0.9R_(c), or such that 0.1R_(c)≤W₂≤0.9R_(c).Additionally, width W₂ may be 0.5R_(c)≤W₂≤0.9R_(c). According toembodiments of the present disclosure, a wider nano-structured region 26provides a higher scattering-induced attenuation for the same density ofnano-sized structures 32. The radial width W₂ of nano-structured region26 may be greater than about 1.0 μm. For example, W₂ may be betweenabout 5.0 μm and about 300 μm, such as less than about 200 μm. W₂ mayalso be, for example, between about 2.0 μm and about 100 μm, betweenabout 2.0 μm and about 50 μm, between at least 2.0 μm and about 20 μm,or even between about 2.0 μm and about 12 μm. W₂ may be, for example, atleast about 7.0 μm. The core inner annular region 28 may have a width W₃such that W₃=R₃−R₂ and has a midpoint R_(3MID)=(R₂+R₃)/2. The core innerannular region 28 may have a width W₃ such that 0.1R_(c)>W₃>0.9R_(c).For example, W₃ may be between about 1.0 μm and about 100 μm.Additionally, the cladding 40 has a radius R₄, which is also theoutermost periphery of the optical fiber 12. The width of the cladding40, which is equal to R₄−R₃, may be, for example, greater than about 20μm, or greater than about 50 μm, or even greater than about 70 μm.

FIG. 3A is a plot of the exemplary relative refractive index Δ versusfiber radius for an example fiber 12 shown in FIG. 2 (solid line). Thecore 20 may also have a graded core profile, with a-profile having, forexample, α-value between about 1.7 and about 2.3 (e.g., about 1.8 toabout 2.3). Solid central region 22 extends radially outwardly from thecenterline to its outer radius, R₁, and has a relative refractive indexprofile Δ₁(r) corresponding to a maximum refractive index n₁ (andrelative refractive index percent Δ_(1MAX)). According to the embodimentof FIG. 3A, the reference index n_(REF) is the refractive index at thecladding. The nano-structured region 26 has minimum refractive index n₂,a relative refractive index profile Δ₂(r), a maximum relative refractiveindex Δ_(2MAX), and a minimum relative refractive index Δ_(2MIN),wherein some embodiments Δ_(2MAX)=Δ_(2MIN). The core inner annularregion 28 has a maximum refractive index n₃, a relative refractive indexprofile Δ₃(r) with a maximum relative refractive index Δ_(3MAX) and aminimum relative refractive index Δ_(3MIN), wherein some embodimentsΔ_(3MAX)=Δ_(3MIN). As further shown in FIG. 3A, the cladding 40 has arefractive index n₄, a relative refractive index profile Δ₄(r) with amaximum relative refractive index Δ_(4MAX) and a minimum relativerefractive index Δ_(4MIN). In some embodiments, Δ_(4MAX)=Δ_(4MIN). Insome embodiments, Δ_(1MAX)>Δ_(4MAX) and Δ_(3MAX)>Δ_(4MAX). In someembodiments Δ_(2MIN)>Δ_(4MAX). In the embodiment shown in FIGS. 2 and3A, Δ_(1MAX)>Δ_(3MAX)>Δ_(2MAX)>Δ_(4MAX), and the refractive indices ofthe regions have the following relationship n₁>n₃>n₂>n₄.

Solid central region 22 and core inner annular region 28 may have asubstantially constant refractive index profile, as shown in FIG. 3Awith a constant Δ₁(r) and Δ₃(r). In addition, Δ₂(r) may be eitherslightly positive (0<Δ₂(r)<0.1%), negative (−0.1%<Δ₂(r)<0), orsubstantially constant. The absolute magnitude of Δ₂(r) may be less thanabout 0.1%, for example, less than about 0.05%. According to embodimentsof the present disclosure, absolute magnitude of Δ₂(r) may be less thanabout 0.025%, or even less than about 0.01%, for more than about 50% ofthe radial width of the nano-structured ring portion 26. The cladding 40may have a substantially constant refractive index profile, as shown inFIG. 3A with a constant Δ₄(r), where Δ4(r)=0%. In some embodiments thecladding 40 may have a refractive index −0.05%<Δ₄(r)<0.05%. The solidcentral region 22 may have a refractive index where Δ₁(r)>0%.Additionally, nano-structured ring portion 26 may have a relativerefractive index profile Δ2(r) having a negative refractive index withabsolute magnitude less than about 0.05%, and Δ₃(r) of core innerannular region 28 may be, for example, positive or zero. In at leastsome embodiments, n₁>n₂ and n₃>n₄.

FIG. 3B schematically illustrates an exemplary embodiment of lightdiffusing fiber 12. As shown, the fiber 12 includes a core 20 with arelative refractive index Δ₁ and a nano-structured region 26′ situatedover and surrounding the core 20. The core 20 may have a step indexprofile, or a graded core profile, with a-profile having, for example,α-value between about 1.8 and about 2.3. The nano-structured region 26′is an annular ring with a plurality of voids. The width ofnano-structured region 26′ may be as small as about 1.0 μm to about 2.0μm, and may have a negative average relative refractive index Δ₂. Thecladding 40 surrounds the nano-structured region 26′, the cladding 40having a width that may be as small as about 1.0 μm. The cladding 40 mayhave a negative, a positive or a substantially constant relativerefractive index. The main difference between the examples shown inFIGS. 3A and 3B is that nano-structured region 26 shown in FIG. 3A islocated in the core 20 of the light diffusing fiber 12, andnano-structured region 26′ shown in FIG. 3B is located at the interfaceof the core 20 and the cladding 40. In the direction moving radiallyoutwardly from the centerline, the nano-structured region 26′ beginswhere the relative refractive index of the core first reaches a value ofless than about −0.05%. In the embodiment shown in FIG. 3B, the cladding40 has a relative refractive index profile Δ₃(r) having a maximumabsolute magnitude less than about 0.1%, where Δ_(3MAX)<0.05% andΔ_(3MIN)>−0.05%, and the nano-structured region 26′ ends where theoutmost void occurs in the void-filled region. Additionally, as shown inFIG. 3B, the index of refraction of the core 20 is greater than theindex of refraction n₂ of the nano-structured region 26′, and the indexof refraction n₁ of the cladding 40 is also greater than the index ofrefraction n₂ of nano-structured region.

FIG. 3C illustrates an embodiment of an optical fiber 12 in accordancewith the present disclosure. The fiber 12, which was made, has a coreregion 22, a nano-structured region 26, a third core region 26 and apolymer cladding 40. The fiber 12 had a first core region 22 with anouter radius R₁ of about 33.4 μm, a nano-structured region 26 with anouter radius R₂ of about 42.8 μm, a third core region 28 with an outerradius R₃ of about 62.5 μm, and a polymer cladding 40 (not shown) withan outer radius R₄ of about 82.5 μm. The material of the core was puresilica, the material of the cladding 40 was a low index polymer (e.g.,UV curable silicone having a refractive index of 1.413 commerciallyavailable from Dow-Corning of Midland, Mich. under product nameQ3-6696). The fiber 12 had an NA of 0.3. The fiber 12 includednano-sized structures containing SO₂ gas. Applicants found that filledSO₂ voids in the nano-structured ring 26 greatly contribute toscattering. Furthermore, when SO₂ gas was used to form thenano-structures, it has been discovered that this gas allows a thermallyreversible loss to be obtained, i.e., below 600° C. the nano-structuredfiber scatters light, but above 600° C. the same fiber will guide light.This unique behavior that SO₂ imparts is also reversible, in that uponcooling the same fiber below 600° C., the fiber 12 will act as lightdiffusing fiber and will again generate an observable scattering effect.

The light diffusing fiber 12 according to embodiments of the presentdisclosure can be made by methods which utilize preform consolidationconditions which result in a significant amount of gases being trappedin the consolidated glass blank, thereby causing the formation of voidsin the consolidated glass optical fiber preform. Rather than takingsteps to remove these voids, the resultant preform is used to form anoptical fiber with voids, or nano-sized structures, therein. Theresultant fiber's nano-sized structures or voids are utilized to scatteror guide the light out of the fiber, via its sides, along the fiberlength. That is, the light is guided away from the core 20, through theouter surface of the fiber, to provide desired illumination.

As used herein, the diameter of a nano-sized structure such as a void isthe longest line segment contained within the nano-sized structure whoseendpoints are at the boundary of the nano-sized structure when theoptical fiber is viewed in perpendicular cross-section transverse to thelongitudinal axis of the fiber. A method of making optical fibers withnano-sized voids is described, for example, in U.S. Patent ApplicationPublication No. 2007/0104437 A1, which is incorporated herein byreference.

According to embodiments of the present disclosure, light diffusingfiber 12 provides uniform illumination along the length of the fiber 12.The light scattering axially from the surface of the fiber has avariation relative to the mean scattering intensity that is less thanabout 50%, less than about 30%, less than about 20%, or even less thanabout 10%. The dominant scattering mechanism in conventionalsilica-based optical fibers without nano-sized structures is Rayleighscattering, which has a broad angular distribution. The uniformity ofillumination along the fiber length may be controlled such that theminimum scattering illumination intensity is not less than about 0.7 ofthe maximum scattering illumination intensity. As described below, suchminimum scattering illumination intensity may be achieved by controllingfiber tension during the draw process, or by selecting the appropriatedraw tension. Appropriate draw tensions may be, for example, betweenabout 30 g and about 100 g, or between about 40 g and about 90 g.

FIG. 4A is a plot of attenuation versus wavelength for a fiber such asshown in FIG. 3C which included SO₂ gas filled voids. The figure depictsattenuation as a function of wavelength for a light diffusing fiber 12drawn at a tension of 90 g and a light diffusing fiber 12 drawn at atension of 400 g. FIG. 4A illustrates that light diffusing fibers 12 canachieve very large scattering losses, and thus can provide highillumination intensity, in the visible wavelength range. Morespecifically, FIG. 4A illustrates that higher fiber draw tensions resultin lower scattering losses and that lower fiber draw tensions result ina fiber section with higher scattering loss, and thus, strongerillumination.

FIG. 4B is a plot of attenuation versus wavelength for a light diffusingfiber 12 drawn at a tension of 90 g, a light diffusing fiber 12 drawn ata tension of 40 g, a comparative multiple mode fiber (labeled fiber A)with normalized loss, and a theoretical fiber having a loss dependenceof 1/

. The light diffusing fibers 12 shown in FIG. 4B included nano-sizedstructures containing SO₂ gas. (The graph of FIG. 4B depicts wavelengthdependence of the loss. In this example, in order to compare the slopeof the scattering for the light fiber 12 and fiber A, the loss of lowloss fiber (fiber A) was multiplied by a factor of 20, so that the twoplots can be easily shown in the same Figure). As shown, the averagespectral attenuation from 400 nm to 1100 nm was about 0.4 dB/m for thefiber drawn with a tension of about 40 g, and was about 0.1 dB/m for thefiber drawn with a tension of about 90 g. FIG. 4B illustrates thatoptical fiber 12 has a relatively flat (weak) dependence on wavelengthas compared to standard single-mode transmission fiber, such as forexample, SMF-28e^(R) fiber. In standard single mode or multimode opticalfibers, the losses at wavelengths less than about 1300 nm are dominatedby Rayleigh scattering. These Rayleigh scattering losses are determinedby the properties of the material and are typically about 20 dB/km forvisible wavelengths between about 400 nm and about 700 nm where Rayleighscattering losses are proportional to

^(−p), where p is about 4. In contrast, light diffusing fiber 12according to the present disclosure, have scattering losses proportionalto 1/

^(−p), where p is less than 2, less than 1, or even more less than 0.5.According to embodiments of the present disclosure, p may be less than2, less than 1, or even more less than 0.5 over at least about 80% ofthe wavelength range of 400 nm-1100 nm.

Without being bound to any particular theory, it is believed that theincrease in the scattering losses when the draw tension decreases, forexample from about 90 g to about 40 g, is due to an increase in theaverage diameter of the nanostructures. Therefore, this effect of fibertension could be used to produce constant attenuation along the lengthof the fiber by varying the fiber tension during the draw process. Forexample, a first fiber segment drawn at high tension, T₁, with a loss ofα₁ and length, L₁, will attenuate the optical power from an input levelP0 to P0 exp(−α₁*L₁/4.343). A second fiber segment optically coupled tothe first fiber segment and drawn at lower tension T₂ with a loss of α₂and length L₂ will further attenuate the optical power from P0exp(−α₁*L₁/4.343) to P0 exp(−α₁*_(L)1/40.343) exp(−α₂*L₂/4.343). Thelengths and attenuations of the first and second fiber segments can beadjusted to provide uniform intensity along the length of theconcatenated fiber.

Embodiments of the present disclosure further relate to medical deviceshaving interior channels, and to systems for disinfecting medicaldevices having interior channels. For ease of discussion, a flexibleendoscope is used to illustrate such medical devices. However, it shouldbe understood that embodiments of the present disclosure may include anymedical device having at least one interior channel, and particularly tomedical devices which are conventionally used to perform more than oneprocedure such that it is recommended that they be disinfected betweenuses. For example, such medical devices may also be, but are not limitedto, laparoscopic devices, indwelling catheters, non-indwellingcatheters, IV and other medical tubing (i.e. feeding or ventilationtubes), luminal surgical equipment, dental devices, arthroscopicshavers, and inflow/outflow cannulas. Additionally, it should beunderstood that an interior channel is not limited to those of theillustrated flexible endoscope. As used herein, an interior channel maybe, but is not limited to, any passage fluidly connecting one opening ofa medical device to another opening of a medical device.

FIG. 5 is a schematic illustration of an endoscopic surgical systemaccording to an embodiment of the present disclosure. The endoscopicsurgical system includes an endoscope 111 and an operation section 114.The endoscope 111 includes an elongated insertion portion 113 having aproximal end portion configured to be coupled to the operation section114. The insertion portion 113 is configured to be inserted into thebody of a patient. The insertion portion 113 includes an elongatedflexible tube portion 115, a bending portion 116 coupled to a distal endof the flexible tube portion 115, and a distal end hard portion 117coupled to a distal end of the bending portion 116. The operationsection 114 includes features, such as knobs, that control the bendingportion 116 to bend in different directions, such as, but not limitedto, upward, downward, leftward and rightward directions. The operationsection 114 also includes channel port 126 which communicates with a usechannel 150 (shown in FIG. 7) for the insertion of surgical instruments.

FIG. 6 is a front view of a face of the distal end hard portion of anendoscope in accordance with embodiments of the present disclosure. Thedistal end hard portion 117 includes an observation window 118,illumination windows 119 a and 119 b, a use opening 120, and agas-feeding/water-feeding nozzle 121. The configuration of the distalend hard portion 117 shown in FIG. 6 is merely exemplary and is notintended to limit embodiments of the present disclosure to anyparticular configuration. It should be understood that the differentfeatures may be positioned on the face of the distal end hard portion117 in any manner. It should further be understood that some embodimentsof the present disclosure may not include all the features shown in FIG.6 and that various different combinations of the observation window 118,the illumination windows 119 a and 119 b, the use opening 120, and thegas-feeding/water-feeding nozzle 121 are comprehended.

FIG. 7 is a schematic sectional view of the distal end hard portion ofan endoscope according to an embodiment of the present disclosure. Asshown, the observation window 118 may be fitted with an imaging sectionprovided with an optical system such as an objective lens 148 and animaging element such as CCD (not shown). The illumination windows 119 aand 119 b may be fitted with illumination lenses. The endoscopicsurgical system further includes light guides 149 having respective foreend portions disposed in confronting relation with the illuminationlenses of windows 119 a and 119 b. The light guides 149 are detachablyconnectable to a light source and transmit illumination light from thelight source to the respective illumination windows 119 a and 119 b. Thelight guides 149 may be, for example, fiber optic cables, or bundles offiber optic cables. As further shown in FIG. 7, the endoscope includes ause channel 150 which provides a passage for insertion of surgicalinstruments through use opening 120 and into the body of a patient. Theuse channel 150 communicates with channel port 126 and surgicalinstruments may be inserted into channel port 126, through use channel150 and out of use opening 120 during performance of a surgicalprocedure. Additionally, the gas-feeding/water-feeding nozzle 121 isfluidly connected to a source of water through water channel 141 and toa source of gas through gas channel 142.

FIG. 5 also illustrates the insertion of cylindrical optical diffuser129 into an interior channel of the endoscope 111. As shown, thecylindrical optical diffuser 129 is connected to a light source 101which is capable of emitting electromagnetic radiation that is in the UVand/or the short wavelength visible light range of wavelengths. Thecylindrical optical diffuser 129 may be inserted through the channelport 126 and into at least one interior channel of the endoscope 111where the cylindrical optical diffuser 129 emits UV or short wavelengthvisible light to disinfect the at least one interior channel. Forexample, where channel port 126 communicates with the use channel 150for insertion of surgical instruments as described above, thecylindrical optical diffuser 129 may be inserted through the channelport 126 and into the use channel 150. Light from the light source 101may then be introduced into the cylindrical optical diffuser 129 suchthat the fiber emits UV or short wavelength visible light to disinfectthe use channel 150. According to embodiments of the present disclosure,the endoscope 111 may further include ports in communication with waterchannel 141 and gas channel 142, and at least one cylindrical opticaldiffuser 129 may be inserted through the ports and into water channel141 and gas channel 142 where UV or short wavelength visible light maybe emitted from the cylindrical optical diffuser 129 to disinfect thechannels. Alternatively, the endoscopic surgical system may bedisassembled in order to provide access to use channel 150, waterchannel 141 and/or gas channel 142, and at least one cylindrical opticaldiffuser 129 may be inserted directly into use channel 150, waterchannel 141 and/or gas channel 142 where UV or short wavelength visiblelight may be emitted from the cylindrical optical diffuser 129 todisinfect the channels.

FIG. 8 is a front view of a face of the distal end hard portion of anendoscope in accordance with another embodiment of the presentdisclosure. The distal end hard portion 117 includes an observationwindow 118, illumination windows 119 a and 119 b, a use opening 120, anda gas-feeding/water-feeding nozzle 121. As shown, the endoscope alsoincludes cylindrical optical diffuser 129 physically integrated into theendoscope. The configuration of the integrated cylindrical opticaldiffusers 129 shown in FIG. 8 is merely exemplary and is not intended tolimit embodiments of the present disclosure to any particularconfiguration. It should also be understood that endoscopes according tothe present disclosure could include any number of integratedcylindrical optical diffusers.

FIG. 8 illustrates one exemplary configuration of the cylindricaloptical diffusers physically integrated into a medical device. As shown,the endoscope includes cylindrical optical diffusers disposed in opticalcommunication with the use channel 150, the water channel 141 and thegas channel 142. In the embodiment shown in FIG. 8, at least a portionof the wall of the interior channels are formed from a material that istransmissive to UV and/or short wavelength visible light. As such, lightfor disinfecting the interior channels can be transmitted into theinterior channels from the cylindrical optical diffusers which aredisposed outside of the channels. According to another embodiment, thecylindrical optical diffusers may be entirely disposed in the interiorchannels. Alternatively, the cylindrical optical diffusers may bepartially disposed in the interior channels such that the volume of thechannel which is occupied by the fibers is limited. For example, aportion of the cylindrical optical diffusers may be recessed into thewall of the interior channels. It should be understood that endoscopesaccording to the present disclosure may include cylindrical opticaldiffusers integrated into any number of the channels shown in FIG. 8.

Other embodiments of the present disclosure relate to medical deviceshaving interior channels which are positioned in a portion of apatient's body. As explained above, such devices may be, for example,catheters or medical tubing which include an interior channel which hasan interior wall, as well as an exterior wall having surfaces whichdirectly contact a portion of the patient. In such embodiments, theinterior channel of the medical device is formed from a material that istransmissive to UV and/or short wavelength visible light, and thecylindrical optical diffusers may be disposed on the inside or on theoutside of the interior channel. In such embodiments, light fordisinfecting the medical device is transmitted to the surfaces of theinterior wall, as well as to the surfaces of the exterior wall. Thesurfaces of the walls of the interior channel of such medical devicescan be disinfected while maintaining the position of the device in aportion of the patient's body.

In addition to disinfecting the surfaces of the walls of the interiorchannel, the light can also be transmitted out of the interior channelto have a disinfecting effect inside the patient's body. For example,the light may disinfect human body substances such as tissue and fluidsin the patient's body which may contain bacteria. The insertion ofmedical devices into the body of a patient has become common practice inmany fields of medicine, but is also associated with the risk ofbacterial and fungal infections. The mere presence of certain medicaldevices inside a patient's body may promote growth of bacteria byproviding a surface for bacterial adhesion and cause tissue around themedical device to become infected. Similarly, blood, urine, or otherfluids within the patient's body, or fluids being transported into orout of the patient's body through the medical device, may also be, orbecome, infected. One standard response to such infections is to removethe medical device from the patient. However, removing the medicaldevice is not ideal as it defeats the primary purpose of the medicaldevice. Also, due to a variety of circumstances, removing a medicaldevice from some patients is either not possible or not feasible.Alternatively, such infections may be addressed by administeringantimicrobial agents. However, the type of bacteria present in thepatient must be known in order to select antimicrobial agents to whichthe bacteria is susceptible. Use of antimicrobial agents to which thebacteria is resistant would fail to have a disinfecting effect and wouldprolong the infection inside the patient's body. In certain instances,such medical devices may be positioned in a portion of a patient's bodyfor an extended period of time, for example, a period of time longerthan about six hours, and disinfecting the medical device may beperformed to reduce bacteria that may grow or be present on the surfacesof the medical device. In other instances, such medical devices may bepositioned in a portion of a patient's body for the purpose of treatingconditions associated with the presence of bacteria inside the patient,such as in the tissue and/or fluids inside of the patient. Thecylindrical optical diffusers of such medical devices may be configuredto transmit UV and/or short wavelength visible light. However, as it isknown that extended exposure to UV light can be harmful to the health ofa patient, it may be preferable to instead transmit short wavelengthvisible light to disinfect the surfaces of the interior channel whilethe medical device is positioned in a portion of a patient's body. Suchshort wavelength visible light may be, for example, between about 400 nmand about 450 nm, or between about 405 nm and about 415 nm.

According to embodiments of the present disclosure, the cylindricaloptical diffuser may include a coating disposed on an end of thecylindrical optical diffuser opposite an end where light from the lightsource is input into the cylindrical optical diffuser. The coating maycover at least a portion of the end of the cylindrical optical diffusersuch that guided light in the cylindrical optical diffuser is preventedfrom being transmitted out of the end of the cylindrical opticaldiffuser. Where the cylindrical optical diffuser is a side-emittingfiber, the coating may cover an end of at least the core and may cover aportion of the surrounding cladding. The coating may be, for example, areflective coating or an absorptive coating. In certain applications ofembodiments of the present disclosure, it may be advantageous to limitthe transmission of light from the end of the cylindrical opticaldiffuser such that substantially all light emitted from the diffuser isemitted through the outer surface of the diffuser.

Embodiments of the present disclosure also relate to disinfectionmethods. A method according to the present disclosure includes insertingat least a portion of at least one cylindrical optical diffuser into aninterior channel of a medical device. For purposes of the presentdisclosure, inserting at least a portion of at least one cylindricaloptical diffuser into an interior channel of a medical device mayinclude any manual or automated process for introducing the cylindricaloptical diffuser into the interior channel. Additionally, inserting atleast a portion of at least one cylindrical optical diffuser into aninterior channel of a medical device may include providing a medicaldevice with an integrated cylindrical optical diffuser, wherein theintegrated optical diffuser is configured to emit light into theinterior channel. Alternatively, the method may include positioning thecylindrical optical diffuser outside of an interior channel formed froma material that is transmissive to UV and/or short wavelength visiblelight.

The method further includes introducing light from the light source intothe end of the at least one cylindrical optical diffuser opticallycoupled to the light source and emitting the light through the outersurface of the cylindrical optical diffuser to disinfect at least onesurface of the interior channel of the medical device. Light emittedthrough the outer surface of the cylindrical optical diffuser may alsodisinfect human body substances such as tissue and fluids in thepatient's body which may contain bacteria.

The method of the present disclosure includes exposing the interiorchannel of the medical device to a dose of light sufficient to disinfectthe interior channel of the medical device and/or to disinfect humanbody substances in the patient's body. The dose of light may besufficient to reduce greater than 90% of bacteria, fungi, and/or virusesin the interior channel of the medical device. Alternatively, the doseof light may be sufficient to reduce greater than 99% of bacteria,fungi, and/or viruses in the interior channel of the medical device.Where the light is UV light, the dose of light may be, for example,greater than about 5 mJ/cm², such as between about 5 mJ/cm² and about175 mJ/cm². The dose of light may be between about 10 mJ/cm² and about150 mJ/cm², or even between about 15 mJ/cm² and about 80 mJ/cm². Wherethe light is short wavelength visible light the dose of light may be,for example, greater than about 25 J/cm², such as between about 25 J/cm²and about 250 J/cm². The dose of light may be between about 50 J/cm² andabout 215 J/cm², or even between about 75 J/cm² and about 190 J/cm².

Exposing the interior channel of the medical device to a dose of lightsufficient to disinfect the interior channel of the medical deviceand/or to disinfect human body substances in the patient's body may beperformed for any exposure time. However, the exposure time may be, forexample, greater than 4.0 minutes, such as between about 4.0 minutes andabout 24 hours. The exposure time may be between about 30 minutes andabout 12 hours, or even between about 1.0 hour and about 6.0 hours.

According to an aspect (1) of the present disclosure, a system fordisinfecting a medical device is provided. The system comprises a lightsource that generates light having at least one wavelength between about100 nm and about 500 nm; and at least one cylindrical optical diffuserdisposed in optical communication with at least one interior channel ofa medical device, the at least one cylindrical optical diffuser havingan outer surface and an end optically coupled to the light source,wherein the at least one cylindrical optical diffuser is configured toscatter guided light through the outer surface to form a light diffuserportion having a length that emits substantially uniform radiation overits length.

According to another aspect (2) of the present disclosure, the system ofaspect (1) is provided, wherein the cylindrical optical diffuser has ascattering-induced attenuation greater than about 50 dB km.

According to another aspect (3) of the present disclosure, the system ofany of aspects (1)-(2) is provided, wherein the cylindrical opticaldiffuser radiation is substantially uniform, such that the differencebetween the minimum and maximum scattering illumination intensity isless than about 30% of the maximum scattering illumination intensity.

According to another aspect (4) of the present disclosure, the system ofany of aspects (1)-(3) is provided, wherein the at least one cylindricaloptical diffuser comprises a light diffusing optical fiber having acore, a primary cladding, and a plurality of nano-sized structures, andwherein the guided light is scattered through the outer surface via thenano-sized structures away from the core.

According to another aspect (5) of the present disclosure, the system ofaspect (4) is provided, wherein the nano-sized structures are situatedin the core.

According to another aspect (6) of the present disclosure, the system ofany of aspects (4)-(5) is provided, wherein the nano-sized structuresare gas filled voids having a diameter of greater than about 10 nm.

According to another aspect (7) of the present disclosure, the system ofany of aspects (1)-(6) is provided, wherein an end of the at least onecylindrical optical diffuser opposite the end optically coupled to thelight source is coated with a reflective coating.

According to another aspect (8) of the present disclosure, the system ofany of aspects (1)-(7) is provided, wherein an end of the at least onecylindrical optical diffuser opposite the end optically coupled to thelight source is coated with an absorptive coating.

According to another aspect (9) of the present disclosure, the system ofany of aspects (1)-(8) is provided, wherein the at least one cylindricaloptical diffuser comprises an outer coating, wherein the outer coatingis a resin that transmits UV light.

According to another aspect (10) of the present disclosure, the systemof aspect (9) is provided, wherein the resin that transmits UV light isselected from the group consisting of resins having structutes oftripropylene glycol diacrylate (TPGDA), polyester tetraacrylate,polyester hexaacrylate, aliphatic urethane diacrylate+hexanedioldiacrylate, polyether tetraacrylate, silicone diacrylate, siliconehexaacrylate, epoxydiacrylate based on bisphenol A, and epoxydiacrylatebased on bisphenol A+25% TPGDA.

According to another aspect (11) of the present disclosure, the systemof any of aspects (1)-(10) is provided, wherein the light sourcegenerates light having at least one wavelength between about 100 nm andabout 400 nm.

According to another aspect (12) of the present disclosure, the systemof any of aspects (1)-(11) is provided, wherein the light sourcegenerates light having at least one wavelength between about 100 nm andabout 290 nm.

According to another aspect (13) of the present disclosure, the systemof any of aspects (1)-(10) is provided, wherein the light sourcegenerates light having at least one wavelength between about 400 nm andabout 500 nm.

According to another aspect (14) of the present disclosure, a medicaldevice is provided. The medical device comprises at least one interiorchannel, and at least one cylindrical optical diffuser disposed inoptical communication with the least one interior channel, the at leastone cylindrical optical diffuser having an outer surface and an endoptically coupled to a light source, wherein the at least onecylindrical optical diffuser is configured to scatter guided lightthrough the outer surface to form a light diffuser portion having alength that emits substantially uniform radiation over its length

According to another aspect (15) of the present disclosure, the medicaldevice of aspect (14) is provided, wherein the at least one cylindricaloptical diffuser is disposed outside of the at least one interiorchannel.

According to another aspect (16) of the present disclosure, the medicaldevice of aspect (14) is provided, wherein the at least one cylindricaloptical diffuser is disposed inside of the at least one interiorchannel.

According to another aspect (17) of the present disclosure, the medicaldevice of aspect (16) is provided, wherein the at least one cylindricaloptical diffuser is partially disposed inside of the at least oneinterior channel.

According to another aspect (18) of the present disclosure, the medicaldevice of any of aspects (14)-(17) is provided, wherein the at least oneinterior channel comprises a wall, wherein at least a portion of thewall comprises a material transmissive to light having at least onewavelength between about 100 nm and about 500 nm.

According to another aspect (19) of the present disclosure, the medicaldevice of any of aspects (14)-(18) is provided, wherein the cylindricaloptical diffuser has a scattering-induced attenuation greater than about50 dB km.

According to another aspect (20) of the present disclosure, the medicaldevice of any of aspects (14)-(19) is provided, wherein the cylindricaloptical diffuser radiation is substantially uniform, such that thedifference between the minimum and maximum scattering illuminationintensity is less than about 30% of the maximum scattering illuminationintensity.

According to another aspect (21) of the present disclosure, the medicaldevice of any of aspects (14)-(20) is provided, wherein the at least onecylindrical optical diffuser comprises a light diffusing optical fiberhaving a core, a primary cladding, and a plurality of nano-sizedstructures, and wherein the guided light is scattered through the outersurface via the nano-sized structures away from the core.

According to another aspect (22) of the present disclosure, the medicaldevice of aspect (21) is provided, wherein the nano-sized structures aresituated in the core.

According to another aspect (23) of the present disclosure, the medicaldevice of any of aspects (21)-(22) is provided, wherein the nano-sizedstructures are gas filled voids having a diameter of greater than about10 nm.

According to another aspect (24) of the present disclosure, the medicaldevice of any of aspects (14)-(23) is provided, wherein an end of the atleast one cylindrical optical diffuser opposite the end opticallycoupled to the light source is coated with a reflective coating.

According to another aspect (25) of the present disclosure, the medicaldevice of any of aspects (14)-(23) is provided, wherein an end of the atleast one cylindrical optical diffuser opposite the end opticallycoupled to the light source is coated with an absorptive coating.

According to another aspect (26) of the present disclosure, the medicaldevice of any of aspects (14)-(25) is provided, wherein the at least onecylindrical optical diffuser comprises an outer coating, wherein theouter coating is a resin that transmits UV light.

According to another aspect (27) of the present disclosure, the medicaldevice of aspect (26) is provided, wherein the resin that transmits UVlight is selected from the group consisting of resins having structutesof tripropylene glycol diacrylate (TPGDA), polyester tetraacrylate,polyester hexaacrylate, aliphatic urethane diacrylate+hexanedioldiacrylate, polyether tetraacrylate, silicone diacrylate, siliconehexaacrylate, epoxydiacrylate based on bisphenol A, and epoxydiacrylatebased on bisphenol A+25% TPGDA.

According to another aspect (28) of the present disclosure, the medicaldevice of any of aspects (14)-(27) is provided, wherein the light sourcegenerates light having at least one wavelength between about 100 nm andabout 500 nm.

According to another aspect (29) of the present disclosure, the medicaldevice of any of aspects (14)-(28) is provided, wherein the light sourcegenerates light having at least one wavelength between about 100 nm andabout 400 nm.

According to another aspect (30) of the present disclosure, the medicaldevice of any of aspects (14)-(29) is provided, wherein the light sourcegenerates light having at least one wavelength between about 100 nm andabout 290 nm.

According to another aspect (31) of the present disclosure, the medicaldevice of any of aspects (14)-(28) is provided, wherein the light sourcegenerates light having at least one wavelength between about 400 nm andabout 500 nm.

According to another aspect (32) of the present disclosure, adisinfection method is provided. The disinfection method comprisesinserting at least a portion of at least one cylindrical opticaldiffuser into an interior channel of a medical device, and introducinglight from a light source into an end of the at least one cylindricaloptical diffuser optically coupled to the light source and emitting thelight through the outer surface of the diffuser to illuminate a portionof the diffuser and to expose the interior channel to the emitted light,wherein the at least one cylindrical optical diffuser is configured toscatter guided light through the outer surface to form a light diffuserportion having a length that emits substantially uniform radiation overits length, and to disinfect at least one surface of the interiorchannel.

According to another aspect (33) of the present disclosure, thedisinfection method of aspect (32) is provided, wherein the at least onecylindrical optical diffuser comprises a light diffusing optical fiberhaving a core, a primary cladding, and a plurality of nano-sizedstructures, and wherein the guided light is scattered through the outersurface via the nano-sized structures away from the core.

According to another aspect (34) of the present disclosure, thedisinfection method of any of aspects (32)-(33) is provided, whereinintroducing light from the light source is performed while at least aportion of the medical device is positioned in the body of a patient.

According to another aspect (35) of the present disclosure, thedisinfection method of any of aspects (32)-(34) is provided, wherein theat least one cylindrical optical diffuser is configured to scatterguided light through the outer surface to disinfect human bodysubstances.

According to another aspect (36) of the present disclosure, thedisinfection method of aspect (35) is provided, wherein the human bodysubstances are tissue within the body of the patient.

According to another aspect (37) of the present disclosure, thedisinfection method of aspect (35) is provided, wherein the human bodysubstances are fluids within the body of the patient.

According to another aspect (38) of the present disclosure, thedisinfection method of any of aspects (32)-(37) is provided furthercomprising exposing the interior channel to a dose of light that isgreater than about 5 mj/cm².

According to another aspect (39) of the present disclosure, thedisinfection method of any of aspects (32)-(38) is provided furthercomprising exposing the interior channel to a dose of light that isbetween about 5 mj/cm² and about 175 mj/cm².

According to another aspect (40) of the present disclosure, thedisinfection method of any of aspects (32)-(39) is provided furthercomprising exposing the interior channel to a dose of light that isbetween about 10 mj/cm² and about 150 mj/cm².

According to another aspect (41) of the present disclosure, thedisinfection method of any of aspects (32)-(40) is provided furthercomprising exposing the interior channel to a dose of light that isbetween about 15 mj/cm² and about 80 mj/cm².

According to another aspect (42) of the present disclosure, thedisinfection method of any of aspects (32)-(41) is provided, whereinintroducing light from a light source comprises introducing light havingat least one wavelength between about 100 nm and about 500 nm.

According to another aspect (43) of the present disclosure, thedisinfection method of any of aspects (32)-(42) is provided, whereinintroducing light from a light source comprises introducing light havingat least one wavelength between about 100 nm and about 400 nm.

According to another aspect (44) of the present disclosure, thedisinfection method of any of aspects (32)-(43) is provided, whereinintroducing light from a light source comprises introducing light havingat least one wavelength between about 100 nm and about 290 nm.

According to another aspect (45) of the present disclosure, thedisinfection method of any of aspects (32)-(42) is provided, whereinintroducing light from a light source comprises introducing light havingat least one wavelength between about 400 nm and about 500 nm.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the present disclosure.

What is claimed is:
 1. A system for disinfecting a medical device, thesystem comprising: a light source that generates light; and at least onecylindrical optical diffuser disposed in optical communication with atleast one interior channel of a medical device, the at least onecylindrical optical diffuser having an outer surface, and an endoptically coupled to the light source, and a scattering-inducedattenuation greater than about 50 dB/km, wherein the at least onecylindrical optical diffuser is configured to scatter guided lightthrough the outer surface to transmit ultraviolet irradiation, or shortwavelength visible light.
 2. The system of claim 1, the at least onecylindrical optical diffuser forms a light diffuser portion having alength that emits substantially uniform radiation over its length suchthat the difference between the minimum and maximum scatteringillumination intensity is less than about 30% of the maximum scatteringillumination intensity.
 3. The system of claim 1, wherein the at leastone cylindrical optical diffuser comprises a light diffusing opticalfiber having a core, a primary cladding, and a plurality of nano-sizedstructures, and wherein the guided light is scattered through the outersurface via the nano-sized structures away from the core.
 4. The systemof claim 3, wherein the nano-sized structures are situated in the core.5. The system of claim 3, wherein the nano-sized structures are gasfilled voids having a diameter of greater than about 10 nm.
 6. Thesystem of claim 1, wherein an end of the at least one cylindricaloptical diffuser opposite the end optically coupled to the light sourceis coated with a reflective coating.
 7. The system of claim 1, whereinan end of the at least one cylindrical optical diffuser opposite the endoptically coupled to the light source is coated with an absorptivecoating.
 8. The system of claim 1, wherein the at least one cylindricaloptical diffuser comprises an outer coating, wherein the outer coatingis a resin that transmits UV light.
 9. The system of claim 8, whereinthe resin that transmits UV light is selected from the group consistingof resins having structutes of tripropylene glycol diacrylate (TPGDA),polyester tetraacrylate, polyester hexaacrylate, aliphatic urethanediacrylate+hexanediol diacrylate, polyether tetraacrylate, siliconediacrylate, silicone hexaacrylate, epoxydiacrylate based on bisphenol A,and epoxydiacrylate based on bisphenol A +25% TPGDA.
 10. The system ofclaim 1, wherein the light source generates light having at least onewavelength between about 100 nm and about 400 nm.
 11. The system ofclaim 1, wherein the light source generates light having at least onewavelength between about 400 nm and about 500 nm.
 12. The system ofclaim 1, wherein ultraviolet irradiation comprises a wavelength of lightless than about 400 nm, and short wavelength visible light comprises awavelength of light in a range from about 400 nm to about 500 nm.
 13. Amedical device comprising: at least one interior channel; and at leastone cylindrical optical diffuser disposed in optical communication withthe least one interior channel, the at least one cylindrical opticaldiffuser having an outer surface, and an end optically coupled to alight source, and a scattering-induced attenuation greater than about 50dB/km, wherein the at least one cylindrical optical diffuser isconfigured to scatter guided light through the outer surface to transmitultraviolet irradiation, or short wavelength visible light.
 14. Themedical device of claim 13, wherein the at least one cylindrical opticaldiffuser is disposed outside of the at least one interior channel. 15.The medical device of claim 13, wherein the at least one cylindricaloptical diffuser is disposed inside of the at least one interiorchannel.
 16. The medical device of claim 15, wherein the at least onecylindrical optical diffuser is partially disposed inside of the atleast one interior channel.
 17. The medical device of claim 13, whereinthe at least one interior channel comprises a wall, wherein at least aportion of the wall comprises a material transmissive to light having atleast one wavelength between about 100 nm and about 500 nm.
 18. Themedical device of claim 13, wherein the cylindrical optical diffuserradiation is substantially uniform, such that the difference between theminimum and maximum scattering illumination intensity is less than about30% of the maximum scattering illumination intensity.
 19. The medicaldevice of claim 13, wherein the at least one cylindrical opticaldiffuser comprises a light diffusing optical fiber having a core, aprimary cladding, and a plurality of nano-sized structures, and whereinthe guided light is scattered through the outer surface via thenano-sized structures away from the core.
 20. The medical device ofclaim 19, wherein the nano-sized structures are situated in the core.21. The medical device of claim 19, wherein the nano-sized structuresare gas filled voids having a diameter of greater than about 10 nm. 22.The medical device of claim 13, wherein an end of the at least onecylindrical optical diffuser opposite the end optically coupled to thelight source is coated with a reflective coating.
 23. The medical deviceof claim 13, wherein an end of the at least one cylindrical opticaldiffuser opposite the end optically coupled to the light source iscoated with an absorptive coating.
 24. The medical device of claim 13,wherein the at least one cylindrical optical diffuser comprises an outercoating, wherein the outer coating is a resin that transmits UV light.25. The medical device of claim 24, wherein the resin that transmits UVlight is selected from the group consisting of resins having structutesof tripropylene glycol diacrylate (TPGDA), polyester tetraacrylate,polyester hexaacrylate, aliphatic urethane diacrylate+hexanedioldiacrylate, polyether tetraacrylate, silicone diacrylate, siliconehexaacrylate, epoxydiacrylate based on bisphenol A, and epoxydiacrylatebased on bisphenol A +25% TPGDA.
 26. The medical device of claim 13,wherein the light source generates light having at least one wavelengthbetween about 100 nm and about 500 nm.
 27. The medical device of claim13, wherein the light source generates light having at least onewavelength between about 400 nm and about 500 nm.
 28. The medical deviceof claim 13, wherein ultraviolet irradiation comprises a wavelength oflight less than about 400 nm, and short wavelength visible lightcomprises a wavelength of light in a range from about 400 nm to about500 nm.
 29. The medical device of claim 28, wherein the short wavelengthvisible light comprises a wavelength in a range from about 400 nm toabout 450 nm, or from about about 405 nm to about 415 nm.
 30. Adisinfection method comprising: inserting at least a portion of at leastone cylindrical optical diffuser into an interior channel of a medicaldevice; and introducing light from a light source into an end of the atleast one cylindrical optical diffuser optically coupled to the lightsource and emitting the light through the outer surface of the diffuserto illuminate a portion of the diffuser and to expose the interiorchannel to the emitted light, wherein the at least one cylindricaloptical diffuser is configured to scatter guided light through the outersurface to transmit ultraviolet irradiation, or short wavelength visiblelight, and to disinfect at least one surface of the interior channel,and wherein the at least one cylindrical optical diffuser has ascattering-induced attenuation greater than about 50 dB/km.
 31. Themethod of claim 30, wherein the at least one cylindrical opticaldiffuser comprises a light diffusing optical fiber having a core, aprimary cladding, and a plurality of nano-sized structures, and whereinthe guided light is scattered through the outer surface via thenano-sized structures away from the core.
 32. The method of claim 30,wherein the at least one cylindrical optical diffuser is configured toscatter guided light through the outer surface to disinfect human bodysubstances.
 33. The method of claim 30, further comprising exposing theinterior channel to a dose of light that is greater than about 5 mj/cm².34. The method of claim 30, further comprising exposing the interiorchannel to a dose of light that is between about 5 mj/cm² and about 175mj/cm².
 35. The method of claim 30, further comprising exposing theinterior channel to a dose of light that is between about 10 mj/cm² andabout 150 mj/cm².
 36. The method of claim 30, further comprisingexposing the interior channel to a dose of light that is between about15 mj/cm² and about 80 mj/cm².
 37. The method of claim 30, whereinintroducing light from a light source comprises introducing light havingat least one wavelength between about 100 nm and about 500 nm.
 38. Themethod of claim 30, wherein ultraviolet irradiation comprises awavelength of light less than about 400 nm, and short wavelength visiblelight comprises a wavelength of light in a range from about 400 nm toabout 500 nm.
 39. The method of claim 38, wherein the short wavelengthvisible light comprises a wavelength in a range from about 400 nm toabout 450 nm, or from about 405 nm to about 415 nm.